Story related and cannot be missed. Just simply play the game.
There are 8 memories in DNA Sequence 9.
Memory 1 - Knowledge is Power
Memory 2 - Damsels in Distress
Memory 3 - Nun the Wiser
Memory 4 - And They're Off
Memory 5 - CTF
Memory 6 - Ribbon Round-Up
Memory 7 - Cheaters Never Prosper
Memory 8 - Having a Blast
When you complete Memory 8, the achievement will unlock.